Can't Get My Tank To Settle Down

[aquabadger]

I started my tank in November 2007. My idea was to have 6 praecox rainbowfish, 5 cherry barbs and 2 thick lipped gouramis. I cycled the tank OK with the 5 cherry barbs and did not lose any of them. In December I added the 6 rainbowfish. Two of them died shortly after. I am pretty sure this was columnaris because I saw stringy bits on their lips. Interpet no8 did seem to sort this out and the tank settled down.

Since August this year I have started to lose cherry barbs and rainbowfish again. I've seen various symptons such as fish hanging near the surface, cloudy eyes, losing their balance and swimming erratically, not eating, resting on the bottom and ulcers. I have tried interpet no7, 8 and 9. Apart from no8 getting rid of the ulcers on the side of rainbowfish none of them have had any effect. The two gourami that I added in March have always been fine.

I don't want to keep putting medicine in, but there seems to be no alternative as they keep getting ill. Since October I've tried adding a carbon filter after the course of medicine to get rid of the medicine and hopefully get the tank back to normal. I've also started adding API stress zyme once a week to keep up the levels of good bacteria in the filter. I have occasionally added aquarium salt to see if that improves things.

I measured all the levels a week ago:
Ammonia 0.0
Nitrite 0.0
Nitrate 20.0
pH 8.0
KH 4°

The high pH has been bugging me so I have tested my tap water and its 7. I had some sort of red rock in the aquarium. I took this out and left it in a bucket of water. The pH did not change in the tank or bucket. I can't think what is my making a pH high. I am tempted to add something to reduce the pH, but everyone seems to advise against that.

The tank is a 125L fluval and has a fluval 3 internal filter. The tank is 80x35x45cm.

I am not sure what to do next. I am thinking of getting rid of the rainbowfish because they just never seem to settle down. I am also wondering whether I should try to reduce the pH. I suppose I could keep live bearers, but I don't really like the look of any of them. African cichlids like high pH, but sound a bit too advanced. The only other fish I can think of that might like a pH of 8 are congo tetras, but some websites recommend a 4ft tank for them. Anyway, basically I'd like to get a settled tank with much less hassle and no dead fish. Any ideas welcome.

At the moment one of the rainbowfish is hanging near the surface and not eating. I've added a dose of melafix which I've not tried before, but I'm getting a bit desparate basically.

 

[waterdrop]

You have not stated what test kit/kits you are using to get the numbers you are presenting. What are your gravel cleaning and filter cleaning habits? Exactly what different types of media do you have in the filter? What temp are you running and what are your flow and turnover rates?

Hopefully some other members will see your answers to these and have ideas or other questions for you.

~~waterdrop~~

 

[aquabadger]

I have a nutrafin test kit for the first 4 tests and a Waterlife kit for the hardness. I clean the gravel and filter every week. I don't get round the whole tank with the gravel cleaner every week so I try to do different areas every week. The filter only has foam pads in it. There is space for one extra media which I use for carbon after a course of meds. Temp is 24C. Not sure about the flow rate, but the tank, heater and filter were sold as a kit so it should all be suitable.

 

[waterdrop]

I assume you squeeze the white (foam/woven floss pads?) out in tank water?

Its a little unusual to clean the filter every single week, do you have any reason to feel it might be too small for the job? Are you getting any reduction in flow at weeks end?

Nothing jumps out yet as being a problem with your water or routines. Perhaps you've truly had bad luck with the health conditions of the particular fish, don't know, perhaps others will think of some other things to ask about. I'm not aware that the cherries, rainbows or gouramis have any particular weaknesses we should be worrying about...

~~waterdrop~~

 

[aquabadger]

I've never noticed the flow rate drop. I guess I thought cleaning the filter every week was the right thing to do. Do you think I should just do it once a month? To rinse it out I just rub off the debris in a bucket of aquarium water while I'm doing the water changes.

 

[drobbyb]

As far as the rainbowfish having that stuff on their lips, that is a sign that you need to do more water changes. You are going to have to do at least 50% water changes every week without fail. Rainbows as a group are sensitive fish. Your pH is fine for rainbows and most other fish so don't worry about that. It's far more important to have a steady pH than one that fluctuates as you try to change it to better suit the fish. It should also be said that if you don't do enough waterchanges your rainbows can get sick and infect the rest of the tank. It's important.

 

[aquabadger]

As far as the rainbowfish having that stuff on their lips, that is a sign that you need to do more water changes. You are going to have to do at least 50% water changes every week without fail. Rainbows as a group are sensitive fish. Your pH is fine for rainbows and most other fish so don't worry about that. It's far more important to have a steady pH than one that fluctuates as you try to change it to better suit the fish. It should also be said that if you don't do enough waterchanges your rainbows can get sick and infect the rest of the tank. It's important.

I haven't seen any stringy stuff since I added 2 more rainbowfish in July and they got it within a week. Interpet no8 did sort that out though. Since October though I have lost 3 rainbows and another one is ill now. They don't get the stringy stuff. Two of them started hanging near the surface for about a week looking sluggish. One got ulcers and a cloudy eye. One lost its balance and couldn't swim properly before passing away.

Because my tap water is 7.0, but for some reason its 7.8-8.0 in the tank I didn't want to do big water changes. I might end up changing the pH from 8.0 to 7.5 over an hour while I do a 50% change? If you don't think that's a problem I could give it a try for a month. At the moment I only change about 15% a week.

 

[drobbyb]

All of the problems are symptoms that you need to do more water changes. Poor water quality over a period of time will kill rainbows.

Also it sounds like you have seashells or coral or something that is driving youre pH up. pH will tend to lower over time due to the biological processes of the bacteria and fish.

 

[OldMan47]

Chances are fairly good that your substrate is the high pH culprit. As others have already urged, a water change is definitely in order any time you see fish hanging at the surface. Take a sample of your substrate, after the water change, and put it in a bucket of tap water overnight . My guess is you will see the pH up a fair bit by morning.

 

[aquabadger]

OK, I'll try weekly 50% water changes from now on. I'll try testing the substrate in a bucket too. I think I just bought the cheapest aquarium gravel in my LFS, so god knows whats in it. You just don't think about these things when you have a new tank. If it is changing the pH is it worth trying a different substrate? Something tells me changing it would be a big job!

 

[drobbyb]

OK, I'll try weekly 50% water changes from now on. I'll try testing the substrate in a bucket too. I think I just bought the cheapest aquarium gravel in my LFS, so god knows whats in it. You just don't think about these things when you have a new tank. If it is changing the pH is it worth trying a different substrate? Something tells me changing it would be a big job!

If it bothers you, you can change the substrate. It can be a messy job but it is possible.

 

[OldMan47]

If you have a substrate that is undermining your ability to have a stable pH, it is time to replace it. As DrobbyB said, it can be a bit of a chore but it can be done.

 

[aquabadger]

OK, but I haven't actually tested the substrate is the cause yet. I'm going to do the first of my 50% water changes tonight. When I've finished that I'll leave some gravel and water in a bucket and test it once a day.

 

[aquabadger]

I have started doing the weekly 50% water changes. The rainbowfish I was worried about has definitely perked up and is eating enthusiastically at every feeding time. Unfortunately one of the other ones died quite suddenly 4 days after the first big water change.

I'm now down to 2 rainbows. Realistically I think I'm going to have to give up on them. Can anyone suggest a tetra or barb that is hardy, about 6-8cm and won't fin nip?

I have tried testing the gravel in a bucket over a few days, but there wasn't a noticable change in the pH. Is there anything else that could cause high pH? I thought I had read somewhere that a high air flow could raise the pH, but I am not sure.

 

[MartinL]

Is the tapwater tested before or after adding the de-chlorinator? I had a problem where the stuff I was using was also raising the pH of the water from 7 to 8. I believe that if your water is quite soft this can make the pH susceptible to change, but if it is stable at 8 it is better to keep it this way rather than try artificially dropping it.